The present invention relates to the suspension of a group of wheels provided with an assembly tie-rod. More particularly, the invention relates to an improvement for positioning a rear arm connected to an end of a torsion bar of the suspension at a predetermined position in the longitudinal direction of a vehicle by a positioning means. The positioning means obviates the installation problems encountered with known devices.
A conventional automobile suspension is disclosed in U.S. Pat. No. 3,831,966. This patent discloses an automobile suspension which includes a forward suspension arm, a torsion bar and a rear arm therein. The torsion bar is mounted rotatably on a body side member through a bearing and includes an end connected to the forward suspension arm and another end connected to the rear arm. The rear arm is mounted on a leaf spring and is fixed on the leaf spring by a tie-rod. A swell of the rear arm is positioned between projections of a complementary part held on the leaf spring, so that any relative movement exerted parallel to the axis of the torsion bar is prevented by the projections of the complementary part.
This conventional automobile suspension requires many components i.e. the complementary part, the leaf spring and the tie-rod, and requires a substantial amount of time and effort for assembly. The assembly is difficult because the rear arm must be fixed by the tie-rod after the complementary part is positioned and held on the leaf spring by the tie-rod.
FIG. 6 shows components arranged around a rear arm 100 of a second Prior Art conventional automobile suspension. This suspension includes a bracket 200 projecting from the inside of a body side member in the lateral direction of a vehicle, a rear arm 100 fitted on the end of a torsion bar 300 and a tie-rod 600 securing the rear arm 100 to the bracket 200. The rear arm 100 includes a pair of vertical plates 120 and a cylinder 130 welded on the vertical plates 120. The cylinder 130 has a pair of outer peripheral recesses 138 on the outside portions thereof, and the bracket 200 includes a pair of vertical portions 220. Each vertical portion 220 of the bracket 200 includes an upper portion 240, and the upper portion 240 of the bracket 200 has a cylindrical upper recess 230. When assembled, the pair of upper portions 240 of the bracket 200 are positioned within the pair of outer peripheral recesses 138 on the cylinder 130 of the rear arm 100.
The rear arm 100 of this automobile suspension is not movable in the axial direction of the torsion bar 300 because the engagement between the pair of outer peripheral recesses 138 formed on the cylinder 130 of the rear arm 100 and the pair of upper portions 240 of the bracket 200 prevents this movement. The pair of outer peripheral recesses 138 required on the cylinder 130 of this conventional suspension reduces the durability of the cylinder 130 of the rear arm 100.
FIG. 7 shows components arranged around a rear arm 100 of another conventional automobile suspension. This automobile suspension includes similar components to the previous automobile suspension. The difference between these automobile suspensions is that this automobile suspension has a pair of stop members 137 on the cylinder 130 instead of the outer peripheral recesses 138 of the previous automobile suspension. Each stop member 137 includes a lateral flange 136 projecting outwardly from the cylinder 130, and an outer surface 135 of the stop member 137 is in contact with an inner surface 225 of the vertical portion 220 of the bracket 200.
Therefore, the rear arm 100 of this automobile suspension is stopped in its movement in the axial direction of the torsion bar 300 by the contact between the pair of outer surfaces 135 of the stop members 137 and the pair of inner surfaces 225 of the bracket 200.
However, this conventional automobile suspension necessiates the pair of stop members 137, and as a result, extra weight is added to the rear arm 100 of the automobile suspension.